In the medical treatment of patients with decubitus ulcers, also referred to as bedsores or pressure sores, it is known that an indication of treatment efficacy is the reduction of the volume of the wound. The wound is usually recessed, where healthy tissue has died, and necrotic tissue or flesh is visible. It has been recognized that a rapid indication of wound volume has a place in the confirmation of the efficacy of the treatment for decubitus ulcers and the like.
Previous methods of measuring wound volume required the use of expensive stereophotogrammetric instrumentation, which also required precision in the set-up of the equipment. The previous methods entailed the use of two cameras positioned at precisely know angles relative to the wound, and relative to each other. The negatives of images taken through the two cameras would then be mounted on a stereophotogrammetric viewer which was manually manipulated to yield measurements. "Evaluation of Leg Ulcer Treatment with Stereophotogrammetry", G. Eriksson et al, British Journal of Dermatology 101, 123 (1979) gives details of this method. Another prior method, "Acceleration of Wound Healing in Man with Zinc Sulfate Given by Mouth", W.J. Pories et al, The Lancet 1, 7482, (1967), involved the making of a cast of the wound and then weighing the cast. The cast method is very painful and uncomfortable to the patient, and cannot be used repeatedly on the same patient. Another method includes the use of water or other liquid poured onto the wound. The volume of the liquid used is then measured to determine the volume of the wound. The average physician, even the dermatological specialist lacked the expertise and the time to use these prior art methods.
There are certain desirable characteristics of methods to measure wound volume. The method should be as painless to the patient as possible. The method should require minimum repositioning of the patient. Contact with the wound should be avoided. The accuracy of the method should be sufficient to indicate improvement of the wound status as soon as possible. The time between the collection of data, and the availability of results should be minimal.
It is with this background that the invention was developed during a program to validate the efficacy of a treatment for decubitus ulcers.